Commit | Line | Data |
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e12489f9 | 1 | /* Asynchronous timers. |
acaf905b | 2 | Copyright (C) 2000-2012 Free Software Foundation, Inc. |
e12489f9 GM |
3 | |
4 | This file is part of GNU Emacs. | |
5 | ||
9ec0b715 | 6 | GNU Emacs is free software: you can redistribute it and/or modify |
e12489f9 | 7 | it under the terms of the GNU General Public License as published by |
9ec0b715 GM |
8 | the Free Software Foundation, either version 3 of the License, or |
9 | (at your option) any later version. | |
e12489f9 GM |
10 | |
11 | GNU Emacs is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
9ec0b715 | 17 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
e12489f9 GM |
18 | |
19 | #include <config.h> | |
e12489f9 | 20 | #include <signal.h> |
5890e9f7 | 21 | #include <stdio.h> |
d7306fe6 | 22 | #include <setjmp.h> |
898b4c5c DN |
23 | #include "lisp.h" |
24 | #include "syssignal.h" | |
25 | #include "systime.h" | |
26 | #include "blockinput.h" | |
27 | #include "atimer.h" | |
e12489f9 | 28 | #include <unistd.h> |
e12489f9 | 29 | #include <sys/time.h> |
e12489f9 | 30 | |
e12489f9 GM |
31 | /* Free-list of atimer structures. */ |
32 | ||
33 | static struct atimer *free_atimers; | |
34 | ||
9c2e3e8d GM |
35 | /* List of currently not running timers due to a call to |
36 | lock_atimer. */ | |
37 | ||
38 | static struct atimer *stopped_atimers; | |
39 | ||
e12489f9 GM |
40 | /* List of active atimers, sorted by expiration time. The timer that |
41 | will become ripe next is always at the front of this list. */ | |
42 | ||
43 | static struct atimer *atimers; | |
44 | ||
45 | /* Non-zero means alarm_signal_handler has found ripe timers but | |
46 | interrupt_input_blocked was non-zero. In this case, timer | |
47 | functions are not called until the next UNBLOCK_INPUT because timer | |
48 | functions are expected to call X, and X cannot be assumed to be | |
49 | reentrant. */ | |
50 | ||
51 | int pending_atimers; | |
52 | ||
5f351ff1 | 53 | /* Block/unblock SIGALRM. */ |
e12489f9 GM |
54 | |
55 | #define BLOCK_ATIMERS sigblock (sigmask (SIGALRM)) | |
56 | #define UNBLOCK_ATIMERS sigunblock (sigmask (SIGALRM)) | |
57 | ||
58 | /* Function prototypes. */ | |
59 | ||
f57e2426 J |
60 | static void set_alarm (void); |
61 | static void schedule_atimer (struct atimer *); | |
62 | static struct atimer *append_atimer_lists (struct atimer *, | |
63 | struct atimer *); | |
e192d7d3 | 64 | static void alarm_signal_handler (int signo); |
e12489f9 GM |
65 | |
66 | ||
67 | /* Start a new atimer of type TYPE. TIME specifies when the timer is | |
68 | ripe. FN is the function to call when the timer fires. | |
69 | CLIENT_DATA is stored in the client_data member of the atimer | |
70 | structure returned and so made available to FN when it is called. | |
71 | ||
72 | If TYPE is ATIMER_ABSOLUTE, TIME is the absolute time at which the | |
73 | timer fires. | |
74 | ||
75 | If TYPE is ATIMER_RELATIVE, the timer is ripe TIME s/us in the | |
76 | future. | |
77 | ||
78 | In both cases, the timer is automatically freed after it has fired. | |
79 | ||
80 | If TYPE is ATIMER_CONTINUOUS, the timer fires every TIME s/us. | |
81 | ||
82 | Value is a pointer to the atimer started. It can be used in calls | |
83 | to cancel_atimer; don't free it yourself. */ | |
84 | ||
85 | struct atimer * | |
3e7d6594 | 86 | start_atimer (enum atimer_type type, EMACS_TIME timestamp, atimer_callback fn, |
e5447b22 | 87 | void *client_data) |
e12489f9 GM |
88 | { |
89 | struct atimer *t; | |
90 | ||
91 | /* Round TIME up to the next full second if we don't have | |
92 | itimers. */ | |
93 | #ifndef HAVE_SETITIMER | |
d35af63c PE |
94 | if (EMACS_NSECS (timestamp) != 0 |
95 | && EMACS_SECS (timestamp) < TYPE_MAXIMUM (time_t)) | |
e12489f9 | 96 | { |
3e7d6594 PE |
97 | EMACS_SET_USECS (timestamp, 0); |
98 | EMACS_SET_SECS (timestamp, EMACS_SECS (timestamp) + 1); | |
e12489f9 GM |
99 | } |
100 | #endif /* not HAVE_SETITIMER */ | |
101 | ||
102 | /* Get an atimer structure from the free-list, or allocate | |
103 | a new one. */ | |
104 | if (free_atimers) | |
105 | { | |
106 | t = free_atimers; | |
107 | free_atimers = t->next; | |
108 | } | |
109 | else | |
23f86fce | 110 | t = xmalloc (sizeof *t); |
e12489f9 GM |
111 | |
112 | /* Fill the atimer structure. */ | |
72af86bd | 113 | memset (t, 0, sizeof *t); |
e12489f9 GM |
114 | t->type = type; |
115 | t->fn = fn; | |
116 | t->client_data = client_data; | |
117 | ||
118 | BLOCK_ATIMERS; | |
119 | ||
120 | /* Compute the timer's expiration time. */ | |
121 | switch (type) | |
122 | { | |
123 | case ATIMER_ABSOLUTE: | |
3e7d6594 | 124 | t->expiration = timestamp; |
e12489f9 | 125 | break; |
177c0ea7 | 126 | |
e12489f9 GM |
127 | case ATIMER_RELATIVE: |
128 | EMACS_GET_TIME (t->expiration); | |
3e7d6594 | 129 | EMACS_ADD_TIME (t->expiration, t->expiration, timestamp); |
e12489f9 | 130 | break; |
177c0ea7 | 131 | |
e12489f9 GM |
132 | case ATIMER_CONTINUOUS: |
133 | EMACS_GET_TIME (t->expiration); | |
3e7d6594 PE |
134 | EMACS_ADD_TIME (t->expiration, t->expiration, timestamp); |
135 | t->interval = timestamp; | |
e12489f9 GM |
136 | break; |
137 | } | |
138 | ||
139 | /* Insert the timer in the list of active atimers. */ | |
140 | schedule_atimer (t); | |
141 | UNBLOCK_ATIMERS; | |
142 | ||
143 | /* Arrange for a SIGALRM at the time the next atimer is ripe. */ | |
144 | set_alarm (); | |
177c0ea7 | 145 | |
e12489f9 GM |
146 | return t; |
147 | } | |
148 | ||
149 | ||
150 | /* Cancel and free atimer TIMER. */ | |
151 | ||
152 | void | |
971de7fb | 153 | cancel_atimer (struct atimer *timer) |
e12489f9 | 154 | { |
50b1039f | 155 | int i; |
177c0ea7 | 156 | |
e12489f9 GM |
157 | BLOCK_ATIMERS; |
158 | ||
50b1039f | 159 | for (i = 0; i < 2; ++i) |
94870977 | 160 | { |
50b1039f GM |
161 | struct atimer *t, *prev; |
162 | struct atimer **list = i ? &stopped_atimers : &atimers; | |
177c0ea7 | 163 | |
94870977 | 164 | /* See if TIMER is active or stopped. */ |
4ab1d4be | 165 | for (t = *list, prev = NULL; t && t != timer; prev = t, t = t->next) |
94870977 GM |
166 | ; |
167 | ||
88dbda51 JB |
168 | /* If it is, take it off its list, and put in on the free-list. |
169 | We don't bother to arrange for setting a different alarm time, | |
170 | since a too early one doesn't hurt. */ | |
94870977 GM |
171 | if (t) |
172 | { | |
173 | if (prev) | |
174 | prev->next = t->next; | |
175 | else | |
176 | *list = t->next; | |
177c0ea7 | 177 | |
94870977 GM |
178 | t->next = free_atimers; |
179 | free_atimers = t; | |
4ab1d4be | 180 | break; |
94870977 | 181 | } |
e12489f9 GM |
182 | } |
183 | ||
184 | UNBLOCK_ATIMERS; | |
185 | } | |
186 | ||
187 | ||
3e7d6594 | 188 | /* Append two lists of atimers LIST_1 and LIST_2 and return the |
50b1039f GM |
189 | result list. */ |
190 | ||
191 | static struct atimer * | |
3e7d6594 | 192 | append_atimer_lists (struct atimer *list_1, struct atimer *list_2) |
50b1039f | 193 | { |
3e7d6594 PE |
194 | if (list_1 == NULL) |
195 | return list_2; | |
196 | else if (list_2 == NULL) | |
197 | return list_1; | |
50b1039f GM |
198 | else |
199 | { | |
200 | struct atimer *p; | |
177c0ea7 | 201 | |
3e7d6594 | 202 | for (p = list_1; p->next; p = p->next) |
50b1039f | 203 | ; |
3e7d6594 PE |
204 | p->next = list_2; |
205 | return list_1; | |
50b1039f GM |
206 | } |
207 | } | |
208 | ||
209 | ||
210 | /* Stop all timers except timer T. T null means stop all timers. */ | |
9c2e3e8d GM |
211 | |
212 | void | |
971de7fb | 213 | stop_other_atimers (struct atimer *t) |
9c2e3e8d GM |
214 | { |
215 | BLOCK_ATIMERS; | |
177c0ea7 | 216 | |
9c2e3e8d GM |
217 | if (t) |
218 | { | |
2503c8b1 | 219 | struct atimer *p, *prev; |
177c0ea7 | 220 | |
2503c8b1 | 221 | /* See if T is active. */ |
96013ba9 | 222 | for (p = atimers, prev = NULL; p && p != t; prev = p, p = p->next) |
2503c8b1 GM |
223 | ; |
224 | ||
225 | if (p == t) | |
226 | { | |
227 | if (prev) | |
228 | prev->next = t->next; | |
229 | else | |
230 | atimers = t->next; | |
231 | t->next = NULL; | |
232 | } | |
233 | else | |
234 | /* T is not active. Let's handle this like T == 0. */ | |
235 | t = NULL; | |
9c2e3e8d | 236 | } |
177c0ea7 | 237 | |
50b1039f | 238 | stopped_atimers = append_atimer_lists (atimers, stopped_atimers); |
9c2e3e8d GM |
239 | atimers = t; |
240 | UNBLOCK_ATIMERS; | |
241 | } | |
242 | ||
243 | ||
244 | /* Run all timers again, if some have been stopped with a call to | |
245 | stop_other_atimers. */ | |
246 | ||
e192d7d3 | 247 | static void |
971de7fb | 248 | run_all_atimers (void) |
9c2e3e8d GM |
249 | { |
250 | if (stopped_atimers) | |
251 | { | |
252 | struct atimer *t = atimers; | |
50b1039f | 253 | struct atimer *next; |
177c0ea7 | 254 | |
9c2e3e8d GM |
255 | BLOCK_ATIMERS; |
256 | atimers = stopped_atimers; | |
257 | stopped_atimers = NULL; | |
177c0ea7 | 258 | |
50b1039f GM |
259 | while (t) |
260 | { | |
261 | next = t->next; | |
262 | schedule_atimer (t); | |
263 | t = next; | |
264 | } | |
177c0ea7 | 265 | |
9c2e3e8d GM |
266 | UNBLOCK_ATIMERS; |
267 | } | |
268 | } | |
269 | ||
270 | ||
e192d7d3 | 271 | /* A version of run_all_atimers suitable for a record_unwind_protect. */ |
9c2e3e8d GM |
272 | |
273 | Lisp_Object | |
971de7fb | 274 | unwind_stop_other_atimers (Lisp_Object dummy) |
9c2e3e8d GM |
275 | { |
276 | run_all_atimers (); | |
277 | return Qnil; | |
278 | } | |
279 | ||
280 | ||
e12489f9 GM |
281 | /* Arrange for a SIGALRM to arrive when the next timer is ripe. */ |
282 | ||
283 | static void | |
971de7fb | 284 | set_alarm (void) |
e12489f9 | 285 | { |
e12489f9 GM |
286 | if (atimers) |
287 | { | |
3e7d6594 | 288 | EMACS_TIME now, timestamp; |
e12489f9 GM |
289 | #ifdef HAVE_SETITIMER |
290 | struct itimerval it; | |
291 | #endif | |
292 | ||
293 | /* Determine s/us till the next timer is ripe. */ | |
294 | EMACS_GET_TIME (now); | |
e12489f9 | 295 | |
e12489f9 GM |
296 | /* Don't set the interval to 0; this disables the timer. */ |
297 | if (EMACS_TIME_LE (atimers->expiration, now)) | |
298 | { | |
3e7d6594 PE |
299 | EMACS_SET_SECS (timestamp, 0); |
300 | EMACS_SET_USECS (timestamp, 1000); | |
e12489f9 | 301 | } |
d35af63c PE |
302 | else |
303 | EMACS_SUB_TIME (timestamp, atimers->expiration, now); | |
304 | ||
305 | ||
306 | #ifdef HAVE_SETITIMER | |
177c0ea7 | 307 | |
72af86bd | 308 | memset (&it, 0, sizeof it); |
d35af63c | 309 | it.it_value = make_timeval (timestamp); |
e12489f9 GM |
310 | setitimer (ITIMER_REAL, &it, 0); |
311 | #else /* not HAVE_SETITIMER */ | |
3e7d6594 | 312 | alarm (max (EMACS_SECS (timestamp), 1)); |
e12489f9 GM |
313 | #endif /* not HAVE_SETITIMER */ |
314 | } | |
315 | } | |
316 | ||
317 | ||
318 | /* Insert timer T into the list of active atimers `atimers', keeping | |
319 | the list sorted by expiration time. T must not be in this list | |
320 | already. */ | |
321 | ||
322 | static void | |
971de7fb | 323 | schedule_atimer (struct atimer *t) |
e12489f9 GM |
324 | { |
325 | struct atimer *a = atimers, *prev = NULL; | |
326 | ||
327 | /* Look for the first atimer that is ripe after T. */ | |
328 | while (a && EMACS_TIME_GT (t->expiration, a->expiration)) | |
329 | prev = a, a = a->next; | |
330 | ||
331 | /* Insert T in front of the atimer found, if any. */ | |
332 | if (prev) | |
333 | prev->next = t; | |
334 | else | |
335 | atimers = t; | |
177c0ea7 | 336 | |
e12489f9 GM |
337 | t->next = a; |
338 | } | |
339 | ||
170c80be | 340 | static void |
971de7fb | 341 | run_timers (void) |
e12489f9 GM |
342 | { |
343 | EMACS_TIME now; | |
177c0ea7 | 344 | |
e12489f9 GM |
345 | while (atimers |
346 | && (pending_atimers = interrupt_input_blocked) == 0 | |
d35af63c PE |
347 | && (EMACS_GET_TIME (now), |
348 | EMACS_TIME_LE (atimers->expiration, now))) | |
e12489f9 GM |
349 | { |
350 | struct atimer *t; | |
177c0ea7 | 351 | |
e12489f9 GM |
352 | t = atimers; |
353 | atimers = atimers->next; | |
354 | t->fn (t); | |
177c0ea7 | 355 | |
e12489f9 GM |
356 | if (t->type == ATIMER_CONTINUOUS) |
357 | { | |
358 | EMACS_ADD_TIME (t->expiration, now, t->interval); | |
359 | schedule_atimer (t); | |
360 | } | |
361 | else | |
362 | { | |
363 | t->next = free_atimers; | |
364 | free_atimers = t; | |
365 | } | |
e12489f9 | 366 | } |
177c0ea7 | 367 | |
6bbbda87 CY |
368 | if (! atimers) |
369 | pending_atimers = 0; | |
370 | ||
07a1e794 | 371 | #ifdef SYNC_INPUT |
325530de CY |
372 | if (pending_atimers) |
373 | pending_signals = 1; | |
374 | else | |
375 | { | |
376 | pending_signals = interrupt_input_pending; | |
377 | set_alarm (); | |
378 | } | |
07a1e794 JB |
379 | #else |
380 | if (! pending_atimers) | |
381 | set_alarm (); | |
382 | #endif | |
e12489f9 GM |
383 | } |
384 | ||
385 | ||
170c80be JD |
386 | /* Signal handler for SIGALRM. SIGNO is the signal number, i.e. |
387 | SIGALRM. */ | |
388 | ||
9af30bdf | 389 | void |
971de7fb | 390 | alarm_signal_handler (int signo) |
170c80be | 391 | { |
c2623ee7 YM |
392 | #ifndef SYNC_INPUT |
393 | SIGNAL_THREAD_CHECK (signo); | |
394 | #endif | |
395 | ||
170c80be | 396 | pending_atimers = 1; |
07a1e794 | 397 | #ifdef SYNC_INPUT |
325530de | 398 | pending_signals = 1; |
07a1e794 | 399 | #else |
170c80be JD |
400 | run_timers (); |
401 | #endif | |
402 | } | |
403 | ||
404 | ||
e12489f9 GM |
405 | /* Call alarm_signal_handler for pending timers. */ |
406 | ||
407 | void | |
971de7fb | 408 | do_pending_atimers (void) |
e12489f9 GM |
409 | { |
410 | if (pending_atimers) | |
411 | { | |
412 | BLOCK_ATIMERS; | |
170c80be | 413 | run_timers (); |
e12489f9 GM |
414 | UNBLOCK_ATIMERS; |
415 | } | |
416 | } | |
417 | ||
418 | ||
419 | /* Turn alarms on/off. This seems to be temporarily necessary on | |
420 | some systems like HPUX (see process.c). */ | |
421 | ||
422 | void | |
971de7fb | 423 | turn_on_atimers (int on) |
e12489f9 GM |
424 | { |
425 | if (on) | |
426 | { | |
427 | signal (SIGALRM, alarm_signal_handler); | |
428 | set_alarm (); | |
429 | } | |
430 | else | |
431 | alarm (0); | |
432 | } | |
433 | ||
434 | ||
435 | void | |
971de7fb | 436 | init_atimer (void) |
e12489f9 | 437 | { |
bcdf96ba | 438 | free_atimers = stopped_atimers = atimers = NULL; |
e12489f9 | 439 | pending_atimers = 0; |
325530de | 440 | /* pending_signals is initialized in init_keyboard.*/ |
e12489f9 GM |
441 | signal (SIGALRM, alarm_signal_handler); |
442 | } |